Recently, attempts to reduce the content of oils and fats in emulsion food such as cream or dressing have been made to meet the request of users for low-calorie food. However, a mere reduction in the content of fats and oils in emulsion food causes the resulting emulsion food to lose its inherent rich fatty savor, thus deteriorating its flavor. This is particularly true if the emulsion food is a cream for coffee as the coffee-mildening effect is unfavorably lowered.
In order to solve the disadvantages described above, there has been proposed, for example, a process comprising the use of a thickening agent and a process comprising the employment of multi-phase emulsification such as double emulsification. Although the former process is characterized in that the reduction in the content of fats and oils in emulsion food is compensated for by the addition of a thickening agent, such as gum to enhance the viscosity of the food and thereby retaining the inherent rich fatty savor, the addition of a thickening agent deteriorates the taste and flavor of the emulsion food. On the other hand, the double emulsification method as disclosed in, e.g., Japanese Patent Laid-Open Nos. 169531/1984, 16542/1985, 102137/1985, 184366/1985, 175137/1987, and 22142/1988 is characterized in that the apparent content of fats and oils in an oil-in-water emulsion is enhanced by dispersing another aqueous phase in the oil droplets to thereby retain the inherent rich fatty savor. However, this method is problematic in that the preparation of the emulsion is complicated and that the obtained emulsion is not sufficiently stable, particularly when the emulsion is a high-viscosity one such as mayonnaise.
JP-A 63-301743 discloses a water-in-oil emulsion comprising in the oil phase an edible oil composition comprising 10 to 99 percent by weight, based on the entire oils and fats of the emulsion, of a diglyceride mixture having an increasing melting point of 20 degree centigrade or less. JP-A 63-301765 discloses a highly foamable oil and fat composition comprising an edible oil composition comprising 10 to 99 percent by weight, based on the entire oils and fats of the emulsion, of a diglyceride mixture having an increasing melting point of 20 degree centigrade or below.